When Microsoft released Windows RT last year, its claim to fame was that the operating system included Microsoft Office.

Well. sort of. In the feature tables for Windows RT, the line describing Office inevitably included an asterisk. Microsoft recompiled four programs from the desktop version of Office 2013 to run on Windows RT: Word, Excel, PowerPoint, and OneNote. But a key member of the family, arguably the most important one for prospective business buyers, was missing: Microsoft Outlook.

That omission gets fixed this fall, with the release of Windows 8.1. At Computex 2013, Tami Reller, CFO and CMO of Microsoft’s Windows Division, announced that Outlook 2013 RT will be available on Windows RT devices, as part of the Windows 8.1 update later this year. A preview version of Windows 8.1 will be available at the end of June for Windows 8 and Windows RT devices. A Microsoftspokesperson confirmed that Outlook for Windows RT will indeed be included with the preview.

Owners of existing RT devices will receive the updates for free.

Despite weak sales of its own ARM-powered Surface and even more tepid support from hardware partners, Microsoft doesn't appear to be backing away from Windows RT. The addition of Outlook will undoubtedly convince some previously recalcitrant business buyers that Windows RT tablets make sense, as will the announcement at the Tech-Ed conference this week of management tools that allow greater control over Windows RT devices. And Microsoft also announced support for additional types of Virtual Private Networks (VPNs) on Windows RT.

But there are still dealbreakers that stand in the way of widespread deployments of Windows RT. Office 2013 RT has many of the same features as its x86/x64 counterpart, but it lacks the ability to handle custom macro code. In addition, some features are missing from the RT programs, including the ability to embed audio and video in OneNote notebooks.

And Office is the only desktop app that Microsoft has officially ported to Windows RT. Third-party developers don’t have that option, which means any business that requires a third-party desktop app or a browser plugin other than Adobe Flash is out of luck. Likewise, Windows RT still doesn't support some widely used third-party VPN clients.

There’s also the pesky issue of licensing. The version of Office included with Windows RT is Office Home and Student 2013, which is licensed for noncommercial use only. If you want to stay in the good graces of Microsoft’s licensing agreement, you need to add commercial use rights, through a volume license or by way of a subscription to a business edition of Office 365.

Today’s announcement is also noticeably silent on the question of when Microsoft plans to release native tablet versions of its Office programs, for both Windows 8.1/RT as well as alternative platforms like the iPad and Android tablets. The fact that the desktop version of Outlook is a key part of this fall’s update suggests that Office for tablets won’t appear until 2014, and one recent rumor says late 2014 is the likely target date for those apps.